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Jayapaul J, Schröder L. Molecular Sensing with Host Systems for Hyperpolarized 129Xe. Molecules 2020; 25:E4627. [PMID: 33050669 PMCID: PMC7587211 DOI: 10.3390/molecules25204627] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/27/2020] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Hyperpolarized noble gases have been used early on in applications for sensitivity enhanced NMR. 129Xe has been explored for various applications because it can be used beyond the gas-driven examination of void spaces. Its solubility in aqueous solutions and its affinity for hydrophobic binding pockets allows "functionalization" through combination with host structures that bind one or multiple gas atoms. Moreover, the transient nature of gas binding in such hosts allows the combination with another signal enhancement technique, namely chemical exchange saturation transfer (CEST). Different systems have been investigated for implementing various types of so-called Xe biosensors where the gas binds to a targeted host to address molecular markers or to sense biophysical parameters. This review summarizes developments in biosensor design and synthesis for achieving molecular sensing with NMR at unprecedented sensitivity. Aspects regarding Xe exchange kinetics and chemical engineering of various classes of hosts for an efficient build-up of the CEST effect will also be discussed as well as the cavity design of host molecules to identify a pool of bound Xe. The concept is presented in the broader context of reporter design with insights from other modalities that are helpful for advancing the field of Xe biosensors.
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Affiliation(s)
| | - Leif Schröder
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany;
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2
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Roy S, Appleby KM, Fear EJ, Duckett SB. SABRE-Relay: A Versatile Route to Hyperpolarization. J Phys Chem Lett 2018; 9:1112-1117. [PMID: 29432020 PMCID: PMC5840861 DOI: 10.1021/acs.jpclett.7b03026] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/12/2018] [Indexed: 05/22/2023]
Abstract
Signal Amplification by Reversible Exchange (SABRE) is used to switch on the latent singlet spin order of para-hydrogen (p-H2) so that it can hyperpolarize a substrate (sub = nicotinamide, nicotinate, niacin, pyrimidine, and pyrazine). The substrate then reacts reversibly with [Pt(OTf)2(bis-diphenylphosphinopropane)] by displacing OTf- to form [Pt(OTf)(sub)(bis-diphenylphosphinopropane)]OTf. The 31P NMR signals of these metal complexes prove to be enhanced when the substrate possesses an accessible singlet state or long-lived Zeeman polarization. In the case of pyrazine, the corresponding 31P signal was 105 ± 8 times larger than expected, which equated to an 8 h reduction in total scan time for an equivalent signal-to-noise ratio under normal acquisition conditions. Hence, p-H2 derived spin order is successfully relayed into a second metal complex via a suitable polarization carrier (sub). When fully developed, we expect this route involving a second catalyst to successfully hyperpolarize many classes of substrates that are not amenable to the original SABRE method.
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Barskiy DA, Coffey AM, Nikolaou P, Mikhaylov DM, Goodson BM, Branca RT, Lu GJ, Shapiro MG, Telkki VV, Zhivonitko VV, Koptyug IV, Salnikov OG, Kovtunov KV, Bukhtiyarov VI, Rosen MS, Barlow MJ, Safavi S, Hall IP, Schröder L, Chekmenev EY. NMR Hyperpolarization Techniques of Gases. Chemistry 2017; 23:725-751. [PMID: 27711999 PMCID: PMC5462469 DOI: 10.1002/chem.201603884] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Indexed: 01/09/2023]
Abstract
Nuclear spin polarization can be significantly increased through the process of hyperpolarization, leading to an increase in the sensitivity of nuclear magnetic resonance (NMR) experiments by 4-8 orders of magnitude. Hyperpolarized gases, unlike liquids and solids, can often be readily separated and purified from the compounds used to mediate the hyperpolarization processes. These pure hyperpolarized gases enabled many novel MRI applications including the visualization of void spaces, imaging of lung function, and remote detection. Additionally, hyperpolarized gases can be dissolved in liquids and can be used as sensitive molecular probes and reporters. This Minireview covers the fundamentals of the preparation of hyperpolarized gases and focuses on selected applications of interest to biomedicine and materials science.
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Affiliation(s)
- Danila A Barskiy
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
| | - Aaron M Coffey
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
| | - Panayiotis Nikolaou
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
| | | | - Boyd M Goodson
- Southern Illinois University, Department of Chemistry and Biochemistry, Materials Technology Center, Carbondale, IL, 62901, USA
| | - Rosa T Branca
- Department of Physics and Astronomy, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - George J Lu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Mikhail G Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | | | - Vladimir V Zhivonitko
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Igor V Koptyug
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Oleg G Salnikov
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Kirill V Kovtunov
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Valerii I Bukhtiyarov
- Boreskov Institute of Catalysis SB RAS, 5 Acad. Lavrentiev Pr., 630090, Novosibirsk, Russia
| | - Matthew S Rosen
- MGH/A.A. Martinos Center for Biomedical Imaging, Boston, MA, 02129, USA
| | - Michael J Barlow
- Respiratory Medicine Department, Queen's Medical Centre, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
| | - Shahideh Safavi
- Respiratory Medicine Department, Queen's Medical Centre, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
| | - Ian P Hall
- Respiratory Medicine Department, Queen's Medical Centre, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
| | - Leif Schröder
- Molecular Imaging, Department of Structural Biology, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Eduard Y Chekmenev
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
- Russian Academy of Sciences, 119991, Moscow, Russia
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4
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Marco-Rius I, Bohndiek SE, Kettunen MI, Larkin TJ, Basharat M, Seeley C, Brindle KM. Quantitation of a spin polarization-induced nuclear Overhauser effect (SPINOE) between a hyperpolarized (13) C-labeled cell metabolite and water protons. CONTRAST MEDIA & MOLECULAR IMAGING 2014; 9:182-6. [PMID: 24523064 PMCID: PMC4265858 DOI: 10.1002/cmmi.1556] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/25/2013] [Accepted: 06/22/2013] [Indexed: 01/19/2023]
Abstract
The spin polarization-induced nuclear Overhauser effect (SPINOE) describes the enhancement of spin polarization of solvent nuclei by the hyperpolarized spins of a solute. In this communication we demonstrate that SPINOEs can be observed between [1,4-(13) C2 ]fumarate, hyperpolarized using the dissolution dynamic nuclear polarization technique, and solvent water protons. We derive a theoretical expression for the expected enhancement and demonstrate that this fits well with experimental measurements. Although the magnitude of the effect is relatively small (around 2% measured here), the SPINOE increases at lower field strengths, so that at clinically relevant magnetic fields (1.5-3 T) it may be possible to track the passage through the circulation of a bolus containing a hyperpolarized (13) C-labeled substrate through the increase in solvent water (1) H signal.
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Affiliation(s)
- Irene Marco-Rius
- Department of Biochemistry, University of Cambridge and Cancer Research UK, Cambridge Research InstituteCambridge, UK
| | - Sarah E Bohndiek
- Department of Biochemistry, University of Cambridge and Cancer Research UK, Cambridge Research InstituteCambridge, UK
| | - Mikko I Kettunen
- Department of Biochemistry, University of Cambridge and Cancer Research UK, Cambridge Research InstituteCambridge, UK
| | - Timothy J Larkin
- Department of Biochemistry, University of Cambridge and Cancer Research UK, Cambridge Research InstituteCambridge, UK
| | - Meer Basharat
- Department of Biochemistry, University of Cambridge and Cancer Research UK, Cambridge Research InstituteCambridge, UK
| | - Colm Seeley
- Department of Biochemistry, University of Cambridge and Cancer Research UK, Cambridge Research InstituteCambridge, UK
| | - Kevin M Brindle
- Department of Biochemistry, University of Cambridge and Cancer Research UK, Cambridge Research InstituteCambridge, UK
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5
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Gutmann T, Grünberg A, Rothermel N, Werner M, Srour M, Abdulhussain S, Tan S, Xu Y, Breitzke H, Buntkowsky G. Solid-state NMR concepts for the investigation of supported transition metal catalysts and nanoparticles. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2013; 55-56:1-11. [PMID: 23972428 DOI: 10.1016/j.ssnmr.2013.06.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 06/20/2013] [Accepted: 06/21/2013] [Indexed: 05/24/2023]
Abstract
In recent years, solid-state NMR spectroscopy has evolved into an important characterization tool for the study of solid catalysts and chemical processes on their surface. This interest is mainly triggered by the need of environmentally benign organic transformations ("green chemistry"), which has resulted in a large number of new catalytically active hybrid materials, which are organized on the meso- and nanoscale. Typical examples of these catalysts are supported homogeneous transition metal catalysts or transition metal nanoparticles (MNPs). Solid-state NMR spectroscopy is able to characterize both the structures of these materials and the chemical processes on the catalytic surface. This article presents recent trends both on the characterization of immobilized homogeneous transition metal catalysts and on the characterization of surface species on transition metal surfaces.
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Affiliation(s)
- Torsten Gutmann
- Institute of Physical Chemistry, Technical University Darmstadt, Petersenstrasse 22, D-64287 Darmstadt, Germany
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6
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Desvaux H. Non-linear liquid-state NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2013; 70:50-71. [PMID: 23540576 DOI: 10.1016/j.pnmrs.2012.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 10/31/2012] [Indexed: 06/02/2023]
Affiliation(s)
- Hervé Desvaux
- CEA, IRAMIS, SIS2M, UMR CEA/CNRS 3299, Laboratoire Structure et Dynamique par Résonance Magnétique, CEA/Saclay, Gif-sur-Yvette, France.
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7
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Ledbetter MP, Saielli G, Bagno A, Tran N, Romalis MV. Observation of scalar nuclear spin–spin coupling in van der Waals complexes. Proc Natl Acad Sci U S A 2012; 109:12393-12397. [PMCID: PMC3411965 DOI: 10.1073/pnas.1203108109] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024] Open
Abstract
Scalar couplings between covalently bound nuclear spins are a ubiquitous feature in nuclear magnetic resonance (NMR) experiments, imparting valuable information to NMR spectra regarding molecular structure and conformation. Such couplings arise due to a second-order hyperfine interaction, and, in principle, the same mechanism should lead to scalar couplings between nuclear spins in unbound van der Waals complexes. Here, we report the first observation of scalar couplings between nuclei in van der Waals complexes. Our measurements are performed in a solution of hyperpolarized 129Xe and pentane, using superconducting quantum interference devices to detect NMR in 10 mG fields, and are in good agreement with calculations based on density functional theory. van der Waals forces play an important role in many physical phenomena. The techniques presented here may provide a new method for probing such interactions.
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Affiliation(s)
| | - Giacomo Saielli
- Istituto CNR per la Tecnologia delle Membrane, Sezione di Padova, Via Marzolo, 1-35131 Padova, Italy; and
| | - Alessandro Bagno
- Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo, 1-35131 Padova, Italy
| | - Nhan Tran
- Department of Physics, Princeton University, Princeton, NJ 08544
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8
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Whiting N, Nikolaou P, Eschmann NA, Goodson BM, Barlow MJ. Interdependence of in-cell xenon density and temperature during Rb/129Xe spin-exchange optical pumping using VHG-narrowed laser diode arrays. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 208:298-304. [PMID: 21185208 DOI: 10.1016/j.jmr.2010.11.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 11/23/2010] [Accepted: 11/24/2010] [Indexed: 05/26/2023]
Abstract
The (129)Xe nuclear spin polarization (P(Xe)) that can be achieved via spin-exchange optical pumping (SEOP) is typically limited at high in-cell xenon densities ([Xe](cell)), due primarily to corresponding reductions in the alkali metal electron spin polarization (e.g. P(Rb)) caused by increased non-spin-conserving Rb-Xe collisions. While demonstrating the utility of volume holographic grating (VHG)-narrowed lasers for Rb/(129)Xe SEOP, we recently reported [P. Nikolaou et al., JMR 197 (2009) 249] an anomalous dependence of the observed P(Xe) on the in-cell xenon partial pressure (p(Xe)), wherein P(Xe) values were abnormally low at decreased p(Xe), peaked at moderate p(Xe) (~300 torr), and remained surprisingly elevated at relatively high p(Xe) values (>1000 torr). Using in situ low-field (129)Xe NMR, it is shown that the above effects result from an unexpected, inverse relationship between the xenon partial pressure and the optimal cell temperature (T(OPT)) for Rb/(129)Xe SEOP. This interdependence appears to result directly from changes in the efficiency of one or more components of the Rb/(129)Xe SEOP process, and can be exploited to achieve improved P(Xe) with relatively high xenon densities measured at high field (including averaged P(Xe) values of ~52%, ~31%, ~22%, and ~11% at 50, 300, 500, and 2000 torr, respectively).
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Affiliation(s)
- Nicholas Whiting
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
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9
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Fratila RM, Velders AH. Small-volume nuclear magnetic resonance spectroscopy. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2011; 4:227-249. [PMID: 21391818 DOI: 10.1146/annurev-anchem-061010-114024] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most information-rich analytical techniques available. However, it is also inherently insensitive, and this drawback precludes the application of NMR spectroscopy to mass- and volume-limited samples. We review a particular approach to increase the sensitivity of NMR experiments, namely the use of miniaturized coils. When the size of the coil is reduced, the sample volume can be brought down to the nanoliter range. We compare the main coil geometries (solenoidal, planar, and microslot/stripline) and discuss their applications to the analysis of mass-limited samples. We also provide an overview of the hyphenation of microcoil NMR spectroscopy to separation techniques and of the integration with lab-on-a-chip devices and microreactors.
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Affiliation(s)
- Raluca M Fratila
- MIRA Institute for Biomedical Engineering and Technical Medicine, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands.
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10
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Abstract
One way to overcome the intrinsically low sensitivity of Nuclear Magnetic Resonance spectroscopy is to enhance the signal by dynamic nuclear polarization (DNP), where the polarization of high-gyromagnetic ratio (γ) electrons is transferred to the surrounding nuclei using microwave (MW) irradiation. Recent developments in DNP instrumentations and applications have shown that DNP is one of the most effective methods to increase the nuclear spin polarization in inorganic, organic, and biological materials. It is possible to obtain a solution of molecules containing hyperpolarized nuclei in combination with methods to dissolve rapidly the polarized solid sample. In this chapter, a brief introduction on a theoretical basis and some of new DNP applications in NMR spectroscopy as well as medical applications in Magnetic Resonance Imaging (MRI) are described.
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Lisitza N, Muradian I, Frederick E, Patz S, Hatabu H, Chekmenev EY. Toward 13C hyperpolarized biomarkers produced by thermal mixing with hyperpolarized 129Xe. J Chem Phys 2009; 131:044508. [PMID: 19655895 PMCID: PMC2730707 DOI: 10.1063/1.3181062] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 06/23/2009] [Indexed: 11/15/2022] Open
Abstract
The (13)C NMR signal of acetic acid 1-(13)C-AcH is enhanced by polarization transfer from hyperpolarized (129)Xe using a thermal mixing procedure. 1-(13)C-AcH acid and hyperpolarized (129)Xe are mixed as gases to disperse (129)Xe in the acetic acid. The mixture is frozen with liquid N(2) at 0.5 T. The magnetic field is then momentarily dropped to allow for exchange of spin polarization between (13)C and (129)Xe. After polarization exchange the magnetic field is raised to its original value and the mixture is thawed, resulting in a solution of polarization enhanced 1-(13)C-AcH. A (13)C nuclear spin polarization enhancement of 10 is observed compared to its thermal polarization at 4.7 T. This polarization enhancement is approximately three orders of magnitude lower than that predicted by theory. The discrepancy is attributed to the formation of either an inhomogeneous solid matrix and/or spin dynamics during polarization transfer. Despite the low polarization enhancement, this is the first report of polarization transfer from (129)Xe to (13)C nuclear spins achieved by thermal mixing for a proton-containing molecule of biomedical importance. If future work can increase the enhancement, this method will be useful in hyperpolarizing a wide range of (13)C enriched compounds important in biomedical and biophysical research.
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Affiliation(s)
- Natalia Lisitza
- Enhanced Magnetic Resonance Laboratory, Huntington Medical Research Institutes, Pasadena, California 91105, USA.
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12
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Zhou X, Sun X, Luo J, Zhan M, Liu M. Quantitative estimation of SPINOE enhancement in solid state. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 196:200-203. [PMID: 19058984 DOI: 10.1016/j.jmr.2008.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 11/04/2008] [Accepted: 11/12/2008] [Indexed: 05/27/2023]
Abstract
A theoretical approach to quantitatively estimate the spin polarization enhancement via spin polarization-induced nuclear Overhauser effect (SPINOE) in solid state is presented. We show that theoretical estimates from the model are in good agreement with published experimental results. This method provides a straightforward way to predict the enhanced factor of nuclear magnetic resonance signals in solid state experiments.
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Affiliation(s)
- Xin Zhou
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences, P.O. Box 71010, Wuhan 430071, People's Republic of China.
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13
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Bajaj VS, Hornstein MK, Kreischer KE, Sirigiri JR, Woskov PP, Mak-Jurkauskas ML, Herzfeld J, Temkin RJ, Griffin RG. 250GHz CW gyrotron oscillator for dynamic nuclear polarization in biological solid state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 189:251-79. [PMID: 17942352 PMCID: PMC2695453 DOI: 10.1016/j.jmr.2007.09.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 09/03/2007] [Accepted: 09/13/2007] [Indexed: 05/05/2023]
Abstract
In this paper, we describe a 250 GHz gyrotron oscillator, a critical component of an integrated system for magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments at 9T, corresponding to 380 MHz (1)H frequency. The 250 GHz gyrotron is the first gyro-device designed with the goal of seamless integration with an NMR spectrometer for routine DNP enhanced NMR spectroscopy and has operated under computer control for periods of up to 21 days with a 100% duty cycle. Following a brief historical review of the field, we present studies of the membrane protein bacteriorhodopsin (bR) using DNP enhanced multidimensional NMR. These results include assignment of active site resonances in [U-(13)C, (15)N]-bR and demonstrate the utility of DNP for studies of membrane proteins. Next, we review the theory of gyro-devices from quantum mechanical and classical viewpoints and discuss the unique considerations that apply to gyrotron oscillators designed for DNP experiments. We then characterize the operation of the 250 GHz gyrotron in detail, including its long-term stability and controllability. We have measured the spectral purity of the gyrotron emission using both homodyne and heterodyne techniques. Radiation intensity patterns from the corrugated waveguide that delivers power to the NMR probe were measured using two new techniques to confirm pure mode content: a thermometric approach based on the temperature-dependent color of liquid crystalline media applied to a substrate and imaging with a pyroelectric camera. We next present a detailed study of the mode excitation characteristics of the gyrotron. Exploration of the operating characteristics of several fundamental modes reveals broadband continuous frequency tuning of up to 1.8 GHz as a function of the magnetic field alone, a feature that may be exploited in future tunable gyrotron designs. Oscillation of the 250 GHz gyrotron at the second harmonic of cyclotron resonance begins at extremely low beam currents (as low 12 mA) at frequencies between 320 and 365 GHz, suggesting an efficient route for the generation of even higher frequency radiation. The low starting currents were attributed to an elevated cavity Q, which is confirmed by cavity thermal load measurements. We conclude with an appendix containing a detailed description of the control system that safely automates all aspects of the gyrotron operation.
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Affiliation(s)
- Vikram S. Bajaj
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139
| | - Melissa K. Hornstein
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Kenneth E. Kreischer
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Jagadishwar R. Sirigiri
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Paul P. Woskov
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | | | - Judith Herzfeld
- Department of Chemistry, Brandeis University, Waltham, MA, 02454
| | - Richard J. Temkin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Robert G. Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139
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14
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Glusac K, Goun A, Fayer MD. Photoinduced electron transfer and geminate recombination in the group head region of micelles. J Chem Phys 2006; 125:054712. [PMID: 16942246 DOI: 10.1063/1.2227392] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A pump-probe spectroscopic study of photoinduced forward electron transfer and geminate recombination between donors and acceptors located in the head group regions of micelles is presented. The hole donor is octadecyl-rhodamine B (ODRB) and the hole acceptor is N,N-dimethyl-aniline (DMA). The experiments are conducted as a function of the DMA concentration in the dodecyltrimethylammonium bromide and tetradecyltrimethylammonium bromide micelles. In spite of the fact that the absorptions of both the ODRB radical and ground state bleach spectrally overlap with the ODRB excited state absorption, a procedure that makes it possible to determine the geminate recombination dynamics is presented. These experiments are the first to measure the dynamics of geminate recombination in micelles, and the experiments have two orders of magnitude better time resolution than previous studies of forward transfer. The experimental data are compared to statistical mechanics theoretical calculations of both the forward transfer and the geminate recombination. The theory includes important aspects of the topology of the micelle and the diffusion of the donor-acceptors in the micelle head group region. A semiquantitative but nonquantitative agreement between theory and experiments is achieved.
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Affiliation(s)
- Ksenija Glusac
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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15
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Joo CG, Hu KN, Bryant JA, Griffin RG. In Situ Temperature Jump High-Frequency Dynamic Nuclear Polarization Experiments: Enhanced Sensitivity in Liquid-State NMR Spectroscopy. J Am Chem Soc 2006; 128:9428-32. [PMID: 16848479 DOI: 10.1021/ja0611947] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe an experiment, in situ temperature jump dynamic nuclear polarization (TJ-DNP), that is demonstrated to enhance sensitivity in liquid-state NMR experiments of low-gamma spins--13C, 15N, etc. The approach consists of polarizing a sample at low temperature using high-frequency (140 GHz) microwaves and a biradical polarizing agent and then melting it rapidly with a pulse of 10.6 microm infrared radiation, followed by observation of the NMR signal in the presence of decoupling. In the absence of polarization losses due to relaxation, the enhancement should be epsilon+ = epsilon(T(obs)/T(mu)(wave)), where epsilon+ is the observed enhancement, epsilon is the enhancement obtained at the temperature where the polarization process occurs, and T(mu)(wave) and T(obs) are the polarization and observation temperatures, respectively. In a single experimental cycle, we observe room-temperature enhancements, epsilon(dagger), of 13C signals in the range 120-400 when using a 140 GHz gyrotron microwave source, T(mu)(wave) = 90 K, and T(obs) = 300 K. In addition, we demonstrate that the experiment can be recycled to perform signal averaging that is customary in contemporary NMR spectroscopy. Presently, the experiment is applicable to samples that can be repeatedly frozen and thawed. TJ-DNP could also serve as the initial polarization step in experiments designed for rapid acquisition of multidimensional spectra.
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Affiliation(s)
- Chan-Gyu Joo
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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Ishikawa K, Yamamoto T, Takagi Y. Surface relaxation of polarized Xe atoms dissolved in deuterated ethanol. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2006; 179:234-40. [PMID: 16412672 DOI: 10.1016/j.jmr.2005.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2005] [Revised: 12/02/2005] [Accepted: 12/22/2005] [Indexed: 05/06/2023]
Abstract
We measured the spin relaxation of polarized xenon atoms dissolved in deuterated ethanol. Surface relaxation was suppressed by coating the cell walls with deuterated eicosane. From the dependence of the decay rate on temperature and static magnetic field, we obtained the correlation time of random fluctuations of the local field at the liquid-solid interface. By varying the cell volume, the wall coating, and the surface area of the eicosane, we measured the contribution of the spin-rotation interaction to the relaxation. The use of both deuterated molecules enables us to distinguish surface relaxation from the magnetic dipole-dipole and spin-rotation interactions in solution.
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Affiliation(s)
- Kiyoshi Ishikawa
- Graduate School of Material Science, University of Hyogo, Ako-gun, Hyogo 678-1297, Japan.
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Knagge K, Smith LJ, Raftery D. Substrate and Field Dependence of the SPINOE Transfer to Surface 13C from Hyperpolarized 129Xe. J Phys Chem B 2005; 109:4533-8. [PMID: 16851529 DOI: 10.1021/jp046113c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The substrate and field dependencies of surface SPINOE enhancements using optical pumping and magic angle spinning NMR were monitored. Relaxation rates and enhancements were examined to gain an understanding of the parameters that determine the SPINOE enhancement. (13)C-labeled deuterated methanol was adsorbed on three different substrates (SnO(2), TiO(2), Ti/SiO(2)) with heats of adsorption for xenon ranging from 14.2 to 22.6 kJ/mol. The different heats of adsorption led to a range of xenon coverages and xenon relaxation rates. Using a simple model along with experimental values for the xenon surface polarization and cross- and self-relaxation rates, the (13)C signal enhancement could be predicted and compared with experimental enhancement values. Magnetic field dependence studies were also made by monitoring the (13)C enhancements via SPINOE from hyperpolarized xenon at fields of 0.075, 4.7, and 9.4 T. The pertinent parameters necessary to achieve maximum SPINOE enhancement are discussed.
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Affiliation(s)
- Kevin Knagge
- H. C. Brown Laboratory, Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, USA
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Abstract
Hyperpolarized gases have found a steadily increasing range of applications in nuclear magnetic resonance (NMR) and NMR imaging (MRI). They can be regarded as a new class of MR contrast agent or as a way of greatly enhancing the temporal resolution of the measurement of processes relevant to areas as diverse as materials science and biomedicine. We concentrate on the properties and applications of hyperpolarized xenon. This review discusses the physics of producing hyperpolarization, the NMR-relevant properties of 129Xe, specific MRI methods for hyperpolarized gases, applications of xenon to biology and medicine, polarization transfer to other nuclear species and low-field imaging.
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Affiliation(s)
- Ana-Maria Oros
- Institute of Medicine, Research Centre Jiilich, 52425 Jülich, Germany.
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Ishikawa K, Imai H, Takagi Y. Magnetic resonance imaging of spin-polarization transfer of polarized Xe atoms dissolving into ethanol. J Chem Phys 2004; 120:7602-6. [PMID: 15267672 DOI: 10.1063/1.1687678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We detect the free-induction signals of xenon atoms polarized by spin-exchange optical pumping. The temperature dependence of dissolution and spin-polarization transfer of xenon atoms to ethanol is measured by simultaneous detection of both xenon and proton signals. The polarization of proton is efficiently enhanced in the xenon-saturated solution at low magnetic fields. The large polarization and chemical shift enable us to obtain clearly the distribution image of xenon atoms near the gas-liquid and liquid-liquid boundaries. Therefore the localization of polarized xenon atoms is observed near the surface. By time-resolved magnetic resonance imaging of polarized xenon and polarization-enhanced proton, the spin dynamics is qualitatively studied for the nuclear spins interacting with each other in a dense solution.
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Affiliation(s)
- Kiyoshi Ishikawa
- Department of Material Science, Himeji Institute of Technology, Akogun, Hyogo 678-1297, Japan.
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Han S, Kühn H, Häsing FW, Münnemann K, Blümich B, Appelt S. Time resolved spectroscopic NMR imaging using hyperpolarized 129Xe. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 167:298-305. [PMID: 15040986 DOI: 10.1016/j.jmr.2004.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Revised: 12/19/2003] [Indexed: 05/24/2023]
Abstract
We have visualized the melting and dissolution processes of xenon (Xe) ice into different solvents using the methods of nuclear magnetic resonance (NMR) spectroscopy, imaging, and time resolved spectroscopic imaging by means of hyperpolarized 129Xe. Starting from the initial condition of a hyperpolarized solid Xe layer frozen on top of an ethanol (ethanol/water) ice block we measured the Xe phase transitions as a function of time and temperature. In the pure ethanol sample, pieces of Xe ice first fall through the viscous ethanol to the bottom of the sample tube and then form a thin layer of liquid Xe/ethanol. The xenon atoms are trapped in this liquid layer up to room temperature and keep their magnetization over a time period of 11 min. In the ethanol/water mixture (80 vol%/20%), most of the polarized Xe liquid first stays on top of the ethanol/water ice block and then starts to penetrate into the pores and cracks of the ethanol/water ice block. In the final stage, nearly all the Xe polarization is in the gas phase above the liquid and trapped inside the pores. NMR spectra of homogeneous samples of pure ethanol containing thermally polarized Xe and the spectroscopic images of the melting process show that very high concentrations of hyperpolarized Xe (about half of the density of liquid Xe) can be stored or delivered in pure ethanol.
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Affiliation(s)
- S Han
- Max-Planck Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany
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21
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Heckman JJ, Ledbetter MP, Romalis MV. Enhancement of SQUID-detected NMR signals with hyperpolarized liquid 129Xe in a 1 microT magnetic field. PHYSICAL REVIEW LETTERS 2003; 91:067601. [PMID: 12935108 DOI: 10.1103/physrevlett.91.067601] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2003] [Indexed: 05/24/2023]
Abstract
We report an enhancement of proton NMR signals by a factor of 10(6) by cross polarization with hyperpolarized liquid 129Xe in an ultralow magnetic field of 1 microT. The NMR signals from cyclopentane, acetone, and methanol are detected using a commercial high-T(c) SQUID magnetometer with a signal-to-noise ratio of up to 1000 from a single 90 degrees tipping pulse. This technique allows a wide range of low-field NMR measurements and is promising for the detection of intermolecular scalar spin-spin couplings. Scalar intermolecular couplings can produce a shift of the average NMR frequency in a hyperpolarized sample even in the presence of rapid chemical exchange.
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Affiliation(s)
- J J Heckman
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
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Zook AL, Adhyaru BB, Bowers CR. High capacity production of >65% spin polarized xenon-129 for NMR spectroscopy and imaging. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2002; 159:175-82. [PMID: 12482697 DOI: 10.1016/s1090-7807(02)00030-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A rubidium spin exchange optical pumping system for high capacity production of >65% spin polarized 129Xe gas is described. This system is based on a fiber coupled multiple laser diode array capable of producing an unprecedented 210 W of circularly polarized light at the pumping cell with a laser line width of 1.6 nm. The 129Xe nuclear spin polarization is measured as a function of flow rate, pumping cell pressure, and laser power for varying pumping gas compositions. A maximum 129Xe nuclear polarization of 67% was achieved using a 0.6% Xe mixture at a Xe flow rate of 2.45 sccm. The ability to generate 12% polarized 129Xe at rates in excess of 1L-atm/h is also demonstrated. To achieve production of 129Xe gas at even higher polarization will rely on further optimization of the pumping cell and laser beam geometries in order to mitigate problems associated with temperature gradients that are encountered at high laser power and Rb density.
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Affiliation(s)
- Anthony L Zook
- Chemistry Department and National High Magnetic Field Laboratory, University of Florida, Gainesville, FL 32611-7200, USA
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24
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Goodson BM. Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials, and organisms. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2002; 155:157-216. [PMID: 12036331 DOI: 10.1006/jmre.2001.2341] [Citation(s) in RCA: 299] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The sensitivity of conventional nuclear magnetic resonance (NMR) techniques is fundamentally limited by the ordinarily low spin polarization achievable in even the strongest NMR magnets. However, by transferring angular momentum from laser light to electronic and nuclear spins, optical pumping methods can increase the nuclear spin polarization of noble gases by several orders of magnitude, thereby greatly enhancing their NMR sensitivity. This review describes the principles and magnetic resonance applications of laser-polarized noble gases. The enormous sensitivity enhancement afforded by optical pumping can be exploited to permit a variety of novel NMR experiments across numerous disciplines. Many such experiments are reviewed, including the void-space imaging of organisms and materials, NMR and MRI of living tissues, probing structure and dynamics of molecules in solution and on surfaces, NMR sensitivity enhancement via polarization transfer, and low-field NMR and MRI.
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Affiliation(s)
- Boyd M Goodson
- Materials Sciences Division, Lawrence Berkeley National Laboratory and Department of Chemistry, University of California, Berkeley 94720-1460, USA
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25
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Verhulst AS, Liivak O, Sherwood MH, Chuang IL. A rapid and precise probe for measurement of liquid xenon polarization. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2002; 155:145-149. [PMID: 11945044 DOI: 10.1006/jmre.2002.2515] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The relaxation time of liquid (129)Xe is very long (>15 min) and the signal at thermal equilibrium is weak. Therefore, determination of the absolute polarization enhancement of hyperpolarized (129)Xe by direct measurement is tedious. We demonstrate a fast and precise alternative, based on the dipolar field created by liquid hyperpolarized (129)Xe contained in a cylindrical sample tube. The dipolar field is homogeneous in the bulk of the tube and adds to the external field, causing a shift in the Larmor frequencies of all nuclear spins. We show that the frequency shift of the proton in CHCl(3) (chloroform), which dissolves homogeneously in xenon over a fairly broad temperature range, is an excellent probe for (129)Xe polarization. Frequency measurements are precise and the experiment is much faster than by direct measurement. Furthermore the (129)Xe polarization is minimally disturbed since no rf pulses are applied directly to (129)Xe and since chloroform is a fairly weak source of (129)Xe relaxation. The experiments are reproducible and require only standard NMR instrumentation.
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Affiliation(s)
- Anne S Verhulst
- Solid State and Photonics Laboratory, Stanford University, Stanford, California 94305-4075, USA
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26
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Affiliation(s)
- Yehia Mechref
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
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Appelt S, Haesing F, Baer-Lang S, Shah N, Blümich B. Proton magnetization enhancement of solvents with hyperpolarized xenon in very low-magnetic fields. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)01106-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Leawoods JC, Saam BT, Conradi MS. Polarization transfer using hyperpolarized, supercritical xenon. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00908-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dimitrov IE, Reddy R, Leigh JS. Intermolecular dipole-dipole relaxation of (129)Xe dissolved in water. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2000; 145:302-306. [PMID: 10910698 DOI: 10.1006/jmre.2000.2097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Intermolecular (129)Xe-(1)H nuclear Overhauser effects and (129)Xe longitudinal relaxation time measurements were used to demonstrate that the dipole-dipole coupling is the dominant relaxation mechanism for (129)Xe in water, at room temperature. (129)Xe-(1)H cross-relaxation rates were derived to be sigma(XeH) approximately 3.2 +/- 0.3 x 10(-3) s(-1), independent of xenon pressure (in the range of 1-10 bar) and of the presence of oxygen. Corresponding xenon-proton internuclear distances were calculated to be 2.69 +/- 0.12 A. Using the magnitude of the dipole-dipole coupling and the spin density ratio between dissolved xenon and bulk water, it is estimated that (129)Xe-(1)H spin polarization-induced nuclear Overhauser effects would yield little net proton signal enhancement in water.
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Affiliation(s)
- I E Dimitrov
- Department of Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia 19104, USA
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Lacey ME, Subramanian R, Olson DL, Webb AG, Sweedler JV. High-Resolution NMR Spectroscopy of Sample Volumes from 1 nL to 10 &mgr;L. Chem Rev 1999; 99:3133-3152. [PMID: 11749512 DOI: 10.1021/cr980140f] [Citation(s) in RCA: 211] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael E. Lacey
- Department of Chemistry, Department of Electrical and Computer Engineering, and the Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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Bowers CR, Storhaug V, Webster CE, Bharatam J, Cottone A, Gianna R, Betsey K, Gaffney BJ. Exploring Surfaces and Cavities in Lipoxygenase and Other Proteins by Hyperpolarized Xenon-129 NMR. J Am Chem Soc 1999; 121:9370-7. [PMID: 16429610 PMCID: PMC1317562 DOI: 10.1021/ja991443+] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This paper presents an exploratory study of the binding interactions of xenon with the surface of several different proteins in the solution and solid states using both conventional and hyperpolarized (129)Xe NMR. The generation of hyperpolarized (129)Xe by spin exchange optical pumping affords an enhancement by 3-4 orders of magnitude of its NMR signal. As a result, it is possible to observe Xe directly bound to the surface of micromolar quantities of lyophilized protein. The highly sensitive nature of the (129)Xe line shape and chemical shift are used as indicators for the conditions most likely to yield maximal dipolar contact between (129)Xe nuclei and nuclear spins situated on the protein. This is an intermediate step toward achieving the ultimate goal of NMR enhancement of the binding-site nuclei by polarization transfer from hyperpolarized (129)Xe. The hyperpolarized (129)Xe spectra resulting from exposure of four different proteins in the lyophilized, powdered form have been examined for evidence of binding. Each of the proteins, namely, metmyoglobin, methemoglobin, hen egg white lysozyme, and soybean lipoxygenase, yielded a distinctly different NMR line shape. With the exception of lysozyme, the proteins all possess a paramagnetic iron center which can be expected to rapidly relax the (129)Xe and produce a net shift in its resonance position if the noble gas atom occupies specific binding sites near the iron. At temperatures from 223 to 183 K, NMR signals were observed in the 0-40 ppm chemical shift range, relative to Xe in the gas phase. The signals broadened and shifted downfield as the temperature was reduced, indicating that Xe is exchanging between the gas phase and internal or external binding sites of the proteins. Additionally, conventional (129)Xe NMR studies of metmyoglobin and lipoxygenase in the solution state are presented. The temperature dependence of the chemical shift and line shape indicate exchange of Xe between adsorption sites on lipoxygenase and Xe in the solvent on the slow to intermediate exchange time scale. The NMR results are compared with N(2), Xe, and CH(4) gas adsorption isotherms. It is found that lipoxygenase is unique among the proteins studied in possessing a relatively high affinity for gas molecules, and in addition, demonstrating the most clearly resolved adsorbed (129)Xe NMR peak in the lyophilized state.
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Affiliation(s)
- C R Bowers
- Chemistry Department and National High Magnetic Field Laboratory, University of Florida, Gainesville, Florida 32611-7200, USA
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35
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Seydoux R, Pines A, Haake M, Reimer JA. NMR with a Continuously Circulating Flow of Laser-Polarized 129Xe. J Phys Chem B 1999. [DOI: 10.1021/jp9821984] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Luhmer M, Goodson BM, Song YQ, Laws DD, Kaiser L, Cyrier MC, Pines A. Study of Xenon Binding in Cryptophane-A Using Laser-Induced NMR Polarization Enhancement. J Am Chem Soc 1999. [DOI: 10.1021/ja9841916] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michel Luhmer
- Contribution from the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, and Laboratoire de Chimie Organique E.P., Université Libre de Bruxelles, CP 165/64, Av. F.D. Roosevelt 50, 1050 Bruxelles, Belgium
| | - Boyd M. Goodson
- Contribution from the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, and Laboratoire de Chimie Organique E.P., Université Libre de Bruxelles, CP 165/64, Av. F.D. Roosevelt 50, 1050 Bruxelles, Belgium
| | - Yi-Qiao Song
- Contribution from the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, and Laboratoire de Chimie Organique E.P., Université Libre de Bruxelles, CP 165/64, Av. F.D. Roosevelt 50, 1050 Bruxelles, Belgium
| | - David D. Laws
- Contribution from the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, and Laboratoire de Chimie Organique E.P., Université Libre de Bruxelles, CP 165/64, Av. F.D. Roosevelt 50, 1050 Bruxelles, Belgium
| | - Lana Kaiser
- Contribution from the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, and Laboratoire de Chimie Organique E.P., Université Libre de Bruxelles, CP 165/64, Av. F.D. Roosevelt 50, 1050 Bruxelles, Belgium
| | - Michelle C. Cyrier
- Contribution from the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, and Laboratoire de Chimie Organique E.P., Université Libre de Bruxelles, CP 165/64, Av. F.D. Roosevelt 50, 1050 Bruxelles, Belgium
| | - Alexander Pines
- Contribution from the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Department of Chemistry, University of California, Berkeley, California 94720, and Laboratoire de Chimie Organique E.P., Université Libre de Bruxelles, CP 165/64, Av. F.D. Roosevelt 50, 1050 Bruxelles, Belgium
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Haake M, Goodson BM, Laws DD, Brunner E, Cyrier MC, Havlin RH, Pines A. NMR of supercritical laser-polarized xenon. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)00732-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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